Coated abrasive articles are conventionally coated by either drop coating or electrostatic coating of the abrasive particles onto a resin-coated backing. Of the two methods, electrostatic coating has been often preferred, as it provides some degree of orientation control for grains having an aspect ratio other than one. In general, positioning and orientation of the abrasive particles and their cutting points is important in determining abrasive performance.
PCT International Publ. No. WO 2012/112305 A2 (Keipert) discloses coated abrasive articles manufactured through use of precision screens having precisely spaced and aligned non-circular apertures to hold individual abrasive particles in fixed positions that can be used to rotationally align a surface feature of the abrasive particles in a specific z-direction rotational orientation. In that method, a screen or perforated plate is laminated to an adhesive film and loaded with abrasive particles. The orientation of the abrasive particles could be controlled by the screen geometry and the restricted ability of the abrasive particles to contact and adhere to the adhesive through the screen openings. Removal of the adhesive layer from the filled screen transferred the oriented abrasive particles in an inverted fashion to an abrasive backing. The method relies on the presence of adhesive which may be cumbersome, prone to detackifying (e.g., due to dust deposits) over time, and which may transfer to the resultant coated abrasive article creating the possibility of adhesive transfer to, and contamination of, a workpiece.